This invention relates in general to vehicle transmissions and in particular to an improved structure for a hill holder adapted for use with a manual or automated manual vehicle transmission.
It is well known that a driver of a vehicle having a manual transmission must generally use both feet to operate same. Typically, the right foot is used to operate both the accelerator pedal and the brake pedal, while the left foot is used to operate the clutch pedal. So long as the vehicle is driven over relatively flat terrain, this manipulation of three pedals with two feet is usually not inconvenient. However, when the vehicle is driven over hilly terrain, such operation can be challenging.
For example, to stop the vehicle on an ascending incline, the driver normally uses the left foot to depress the clutch pedal (to disconnect the transmission from the engine) and simultaneously uses the right foot to depress the brake pedal (to stop the vehicle and hold it stationary). Thereafter, to continue up the ascending incline, the driver must rapidly move the right foot from the brake pedal to the accelerator pedal (to increase the speed of the engine) and simultaneously move the left foot to gradually release the clutch pedal (to re-connect the transmission to the engine). This procedure is awkward at best because the weight of the vehicle causes it to roll backward down the incline as soon as the brake pedal is released. As a result, the clutch is often engaged too quickly, causing the vehicle to lurch forward and occasionally causing the engine to stall.
To address this situation, it is known to provide a manual transmission with a mechanism which is commonly referred to as a hill holder. A hill holder is a device which is designed to prevent a vehicle from rolling in a direction which is opposite to the direction for which movement has been selected in the transmission. For example, if a forward gear ratio is selected in the transmission, the hill holder will prevent the vehicle from rolling in the reverse direction, such as might occur in the situation described above. A number of hill holders are known in the art. However, known hill holders are rather complicated, employing a relatively large number of components. As a result, known hill holders are expensive and difficult to construct and maintain. Accordingly, it would be desirable to provide an improved structure for a hill holder which is simpler and less expensive in construction than known structures.